Dose to breast in breast undergoing mantle treatments

There is considerable interest in dose to the breast in patients undergoing mantle treatment for Hodgkin's disease. This is because the patients are quite young (adolescents) and the latency period between irradiation and appearance of tumors is long. In a prospective study TLD chips were placed in several positions on the breast of the patients undergoing mantle treatment. Some parts of the breast were in the irradiated region. TLDs were placed under 2 and 3 cm of superflab bolus. Mantle field is irradiated with 10MV X-rays with a 2 cm spoiler placed 15 cm from the patient's skin. Treatment is given at 120 cm SAD. Doses in the range of 20-30 cGy per fraction were measured underneath the blocks in most cases, and doses of 30-50 cGy were measured at the edge of the block. The prescription is 200 cGy per fraction. The implication of these results will be discussed.